Tablets and powders for cleansing dentures and the like are well known in the art. A common method for using such a product is to place a tablet and a denture in a beaker and then to fill the beaker with water, thereby dissolving the tablet and creating a cleansing bath in which the denture is immersed for a period of from a few minutes to several hours. The aim of a denture cleanser product is to clean the denture as fully and as quickly as possible and especially to remove the accumulation of plaque, mucilaginous and bacterial deposits which collect while the denture is being worn. To wear a denture which has not been completely cleaned of plaque and bacterial deposits is not only unhygienic but can also within a short space of time result in a detrimental effect on the mucous membrane. Consequently, agents which can reduce the adhesion of bacteria to the cleaned denture and thus retard plaque build-up have also been described in the art. Many silicones are suitable for this purpose as described, for example, in WO 96/19563 and WO 96/19191. WO 96/16630 also describes the use of fluorocarbon containing polymers for coating hard tissue and surfaces of the oral environment, including dentures and the like.
To be fully effective, such coatings must be applied uniformly over the whole denture surface. It has now surprisingly been found that the effectiveness of application of such coatings can be enhanced by careful control of the passage of the denture through the air interface of an aqueous bath comprising a polymeric coating agent. In particular, it has been found that coating is enhanced if the denture is withdrawn through the air interface or if the bath is drained from below such that the interface passes over the denture, rather than, for example, decanting the bath contents by tipping. Whilst not wishing to be bound by theory, it is believed that an important factor may be the avoidance of an increase in the surface area of the interface, which could lead to the surface pressure at the interface dropping, whilst the denture passes through it.
Accordingly, it is an object of this invention to provide a method for enhancing the deposition of a polymeric coating on a denture.
It is a further object of this invention to provide a method, for using a denture bath comprising a liquid denture treating composition, to control the interaction of the denture with the air interface of the composition.